For the last several years, the importance of non-traditional renewable and pollution free energy sources is constantly increasing. The global warming effect with its possible relations to people's industrial activities, the rapidly rising demand in oil products in conjunction with the depletion of natural oil resources, environment pollutions caused by burning coal and other hydrocarbon fuels in power stations and in engines of transportation means, and, on the other hand, by highly radioactive waists produced by nuclear reactors, environment alterations caused by many traditional dam hydro-electrical power stations, all together result in acceleration of research and development of solar, wind, thermal, tidal, sea wave and other renewable, clean, and environment friendly energy sources.
Besides, the “oil addictiveness” of industrial and some developing countries leads to political tensions between and inside nations and religions, often being a major contribution in initiating wars, war conflicts, and terrorism. Therefore, it makes the wide use of renewable energy sources (all based on unequal heating of different parts of the earth by the sun's radiation) even more important and desirable. Accordingly, there are many engineering solutions dedicated to development of these sources.
The potential of these energy sources is tremendous. Particularly, as mentioned in U.S. Pat. No. 6,857,266, the size of ocean wave energy only along the coasts of the European Union is estimated to be 219 Gigawatts. Wave energy converters (WECs) with installed capacities of one Megawatt and greater are developed. That patent differentiates three categories of WECs, depending on their location in the sea: “on-shore”, “near shore”, “offshore”. It generally proposes a system of at least two devices: a float and a submerged body adapted to move relative to one another in response to passing waves in the body of liquid, and this relative movement may be harnessed by the linkages between the at least two devices. The system also has a capability to entrap volumes of the surrounding liquid thereby changing hydrodynamic balance associated with a so-called “added mass”. The linkages are adapted to operate a typically hydraulic power take off system driving an electric alternator.
Meanwhile, it mentions a British patent GB 1587344, which presented an idea “to force the phase of a heaving float to follow that of the waves, which had a significantly lower natural frequency (longer period). In this way greatly amplified motions and correspondingly larger power levels were achieved. They disclose the holding of the heaving body at the top or bottom of its cycle by a hydraulically operated latching mechanism (functioning as a parking brake), locking the heaving float to a long rod attached to the bottom of the wave channel. It was then released so that it would resume motion in direction and in phase with the wave. Further theoretical analysis has been completed by various researchers. Two forms of such ‘phase control’ are now recognised, i.e. latching as described and continuous control which may be applied throughout the cycle and may involve power being returned to the heaving device.”
According to the same U.S. Pat. No. 6,857,266, “the apparatus may additionally comprise latching and/or phase control means adapted to assist and optimise the oscillation, amplitude and relative motion of linked devices in varying or heavy sea conditions. This may be effected by using hydraulics or air springs to freeze or temporarily dampen the movements of the devices and or to return power to the apparatus at certain stages in the cycle. The apparatus may also include mooring systems that maintain the complete apparatus in a position that is consistent with statutory requirements and not significantly inhibit its efficient operation. In addition to the aforementioned power take-off linkages, linked devices may also have elastic links or chains or shock absorbers or similar adaptations to absorb excessive relative movements in heave or surge or pitch that may be caused by breaking seas in storm conditions; such elastic links or chains would normally be slack and may be weighted.”
It thus becomes possible to adapt the movement of the float to resemble the wave motion, and to more effectively convert the wave energy into mechanical energy of the float by means of deceleration (braking) and acceleration (releasing) of its movement at predetermined moments of the cycle (phase) with predetermined forces. Both patents: U.S. Pat. No. 6,857,266 and GB 1587344 are herein entirely incorporated by reference.
Another U.S. Pat. No. 6,812,588, hereby also entirely incorporated by reference, describes a WEC selectively adjustable in length, utilizing a downward gravitational force to discharge fluid from a piston assembly connected to a floatation device, which fluid drives a hydraulic power generator that can be used to produce electric energy.
U.S. Pat. No. 6,768,217 describes a WEC comprising a tube vertically movable relative to an anchored float, which tube is reciprocating in response to overpassing waves and driving a transducer for energy generation. The WEC also comprises a motion translator for reducing the transducer's stroke length and magnifying the force transmitted to the transducer, an energy buffer system for limiting the travel of the tube in response to excessively large surface waves, means for adjusting buoyancy in response to changing conditions, a pressure relief valve for automatically reducing excessive tube driving pressures. The U.S. Pat. No. 6,768,217 is also entirely incorporated by reference herein.
U.S. Pat. No. 6,833,631 teaches a vertically extended floating inner member linearly movable relative to an outer member. The relative movement is associated with a relative motion of coils and magnets to generate electrical current, which supplies electrical power for deep-water hydrogen generators in which water is electrolyzed to generate compressed hydrogen gas. This patent disclosure is entirely incorporated by reference herein.
U.S. Pat. No. 4,151,423 discloses a magnetohydrodynamic electric generator for direct energy conversion of saline water kinetic energy flowing through a magnetic field and a sea platform containing a multitude of electricity generators to maximize such conversion. This patent is also incorporated by reference in its entirety.
U.S. Pat. No. 6,515,375 teaches an adaptive wave motion electrical generator comprising wire coil and magnet structure movable relatively to each other and generating electric current. The generator is capable to measure dynamic parameters (relative acceleration, velocity and displacement between the structures) as well as magnitudes of the current and voltage across the coil structure, and the amount of the current is controlled based on the dynamic parameters. The description of U.S. Pat. No. 6,515,375 is hereby entirely incorporated by reference.
There are other several known solutions related to the problems that the present invention concerns with. For instance, U.S. Pat. No. 5,818,132 to Konotchick describes “a linear motion electric power generator for generating electric current from work done by an intermittent force. A moving magnet is confined so that it can move with bidirectional linear, or approximately linear, motion through each of at least two coils. The coils are spaced apart from each other and connected electrically so that the current produced in a first coil as a result of movement of the moving magnet is substantially in phase with current produced in said second coil.” So, a major feature of Konotchick's invention is the movement of magnet(s) inside at least two coils producing, as taught, electric current more efficiently, due to a special distance between the coils and a special way of the coils connection.
Another example of a linear generator based on movement of magnets inside of an inner space of conductive coils is shown in U.S. Pat. No. 6,798,090 to Cheung et al. Its major difference from Konotchick is that it arranges two neighboring moving magnets in opposite polarity, which, according to Cheung, allows intensifying the magnetic flux density in the proximity of the coils. Thus, both inventions utilize the well-known principle of electromagnetic induction resulting in an electric current being inducted in a conductive coil enclosing inside permanent magnets moving relatively to the coil. The faster the magnets move, the greater the electric current is.
Similarly, U.S. Pat. No. 6,921,983 teaches an electric generation device comprising a free flowing magnet and wire coils that capture electrons as the magnet is moved, and transmit the electrons to a diode bridge. The device allows to convert the natural turbulence of a free body of water into AC or DC electric power. According to that patent, it is possible to use a plurality of such generators to form a larger power generating grid.
Analyzing Konotchick in another U.S. Pat. No. 6,952,060 to Goldner et al, hereby entirely incorporated by reference, its authors noticed, that “the reported mechanical and electrical energy conversion for the total generator unit were relatively low, ranging from 2.7 to 4.8%.” Further, Goldner teaches an electric generator and regenerative electromagnetic shock absorber which converts variable frequency repetitive intermittent linear displacement motion to useful electrical power. It provides for superposition of radial components of the magnetic flux density from a plurality of adjacent magnets to produce a maximum average radial magnetic flux density within a coil winding array. It also states that “due to the limitations of current linear motion energy generator devices, it would be advantageous to provide an efficient, variable frequency, regenerative, linear electromagnetic generator with high power generating capacity and high energy conversion efficiency.” It is believed that this statement is still actual.
While the structural arrangements of the above described and many other devices, at first appearance, have similarities with the present invention, they differ in material respects. These differences, which will be described hereinafter, are essential for the effective use of the present invention and which admit of the advantages that are not available with the prior art devices and methods.